LAS VEGAS Labor leaders met at the AFL-CIO's annual convention in Las Vegas yesterday to begin plotting a union organizing strategy around a theme of rebuilding from ruin. AFL-CIO President John Sweeney invoked the September 11 attack on America with a vow to support those who have recently lost their jobs."So to the laid-off workers in this hall tonight, and to workers everywhere who have lost their jobs because of what happened, I want to make a pledge to you on behalf of all of us. Whether you are in tourism, or high-tech, or manufacturing, you can count on us, you can count on your brothers and sisters," Mr. Sweeney said in remarks prepared for an opening speech to about 1,000 union delegates to the convention. The convention opens at a time when union membership stands at 13.5 percent of the work force in 2000, the lowest level in at least a quarter of a century. Mr. Sweeney was elected president of the federation in 1995 with a promise to boost union membership. He is scheduled to be re-elected to a four-year term tomorrow.In addition, more than 900,000 workers have been laid off in the last year because of recession and the effects the September 11 attacks had on industries like hospitality and tourism. Many of them were union workers."We said we had to restore the voices of working families in our workplaces, our communities, our government and in the global marketplace, and we are doing it," Mr. Sweeney said.He also took jabs at the Bush administration for policies the AFL-CIO believes hurt organized labor."President Bush and his administration are doing an excellent job of waging war on the terrorists, and we commend them for that," Mr. Sweeney said. "But at the same time, he and his corporate backers are waging a vicious war on working families, and we condemn them for that." He referred to Mr. Bush's support for a "fast-track" authority that would allow the president to negotiate international trade agreements without the approval of Congresswhen he said, "Let's show President Bush and our allies around the world that we stand together for trade agreements with workers' rights and human rights and environmental protections." The AFL-CIO criticizes the fast-track trade-authority bill pending in Congress as a risk to American jobs that could be lost to overseas competitors.A major thrust of the AFL-CIO's effort during the convention and in the next year will be to regain representation of a greater percentage of the work force by its 66 affiliated unions. The strategy includes putting more money into organizing and forming stronger political bonds with members of Congress.